Micro boring and turning device



May 23, 1944. c. M. KouBA 2,349,503

MICRO BORING' AND TURNING DEVICE Filed Aug. 6, 1943 w y ,7 ,a MzW/Za Patented May 23, 1944 MICRO BORING AND TURNING DEVICE Charles M. Kouba,-Chicago, Ill., assignor of onehalf to Gay M. Bonebrake, Chicago, Ill.

Application August 6, 1943, Serial No. 497,695

8 Claims.

My invention contemplates and provides a m1- cro boring and turning device-i. e., an instrumentality, mountable in the tool post or equivalent part of a lathe or other machine tool, with which may be effected unusually minute and extremely accurate adjustments of a tool with respect to its work piece.

An object of the invention is to provide a micro boring and turning device with the Aaid of which boring and turning operations within tolerances of the order of one ten thousandth of an inch `may be effected as matters of shop routine by machine tool operators endowed with but ordinary mechanical abilities.

Another object of the invention is to provide a micro boring and turning device which is compact, easy to operate, and very sturdily constructed.

Still another object of the invention is to provide, as part of a micro boring and turning device, a novel, simple and remarkably reliable micrometer mechanism.

A preferred embodiment of my invention, which of course may be modified in many particulars within the limits of the appended claims, comprises: (a) a generally U-shaped support having one leg mountable in the tool `post of a lathe or other suitable machine tool, (b) a bell crank lever having one arm substantially longer than the other, pivoted to the support with its long arm disposed alongside that leg of the support which is not mountable in the tool post, (c) a tool mounted inthe short arm of lthe lever, and (d) a unique micrometer mechanism comprising inter alia a duplex screw, acting between the long arm of the lever and an opposed portion of that support leg alongside which the long arm of the lever is disposed.

Other features, objects and advantages of my invention will appear from the following detailed description wherein reference is made to the accompanying sheet of drawings in which:

Figure 1 is a top plan view of the device of the present invention;

Figure 2 is a side elevational view thereof; and

Figure 3 is va view, partly in section and partly in elevation, taken in the vertical plane of line 3-3 of Figure 2 and looking in the direction indicated by the arrows.

Similar reference numerals refer to similar parts throughout the several views.

My new device, in the form thereof depicted by the accompanying drawings, comprises a generally U-shaped one-piece support consisting of a first leg ID, a second and conveniently longer leg `the efllcacy of the lever.

II, and a pair of vertically spaced-apart ears or webs I,2-I2. The support `leg I0 has a transverse cross section approximating that of an ordinary tool shank, so that it may be received and screwclamped in the tool post of a lathe or other machine tool. A conventional tool post and its associated clamping screw are indicated, at I3 and lIii respectively, by dot-and-dash lines in Figures 1 and 2.

A bell crank lever, comprising a short arm I5 and asubstantially longer arm I6, is pvoted in the embrace 0f the ears or webs I 2-I2 by a, conical pin II which occupies accurately machined conical bores in the parts through which it extends and is threaded at its lower end for cooperation with nut ,I B.

Initially the pin Il is snugly rotatable in each of the conical bores through which it extends, .but it may become frozen in either its lever bore, or one or both .of its ear bores, without impairing The opposed plane surfaces of the lever and of the ears between which it is pivoted are accurately nished and snugly contacting.

The arm I I `of the support is preferably provided with a longitudinal rabbet I9 in which the longer arm I6 of the lever` is partially nested.

VA suitable tool 23, for engagement with la work piece, has its shank firmly held by a set screw 2l in an appropriate passage or socket 2| formed in the short arm I5 of the lever.

I shall now describe the novel, simple and remarkably reliable micrometer mechanism to which I .have previously alluded.

The enlarged extremity 22 of the lever I 6 is provided with a vertical bore 23. Snugly disposed in `the bore `23, and oscillatory therein around an axisparallel with the axis of the pivot pin I'I, is a cylinder 24. Axial movement of cylinder .24 is prevented by its integral flange 25 and its cap disc 26 which is held in positionby screw 2l.

Oscillatory cylinder 24 serves as a carrier for a sleeve 28 having diiierential external diameters and, for that reason, is provided with a diametrical'boref29 in which the smaller diameter portion of the sleeve 28 has a force t. Aligned apertures 30 and 3| are formed in the lever extremity 22 to permit the sleeve 28 to be force-fitted into the cylinder 24 as shown, such apertures 3U and 3| fbeing of greater diameters than the sleeve portions which lie therein, and'therefore permitting Aa certain amount of oscillation of the cylinder 24 and sleeve 28, around Athe vertical The threads of the screw portions 33 and 34 are diierentially pitched; e. g., the thread of portion 33 may be one having twenty-nine convolutions per inch and the thread of portion 34 may be one having twenty-eight convolutions per inch.

The smaller diameter portion 34 of the screw has for its nuta cylinder 31 which is disposed in a vertical bore 38 formed in the enlarged extremity 39 of support leg Il. Axial movement of cylinder 31 is prevented by its integral ange di) and its cap disc 4| retained by screw 42. Apertures 43--43, which are formed in the leg support extremity 22, accommodate their screw portion 34 with such clearance as not to interfere with a limited amount of oscillatory movement of cylinder 31 and screw portion 34 with respect to such leg support extremity 22.

Extremely small, and very accurate, adjustments of the tool 20 with respect to its work piece may be effected by manipulation of the screw head 35-the cylinders4 24 and 31 oscillating to prevent any binding of the micrometer screw as tiny modifications of the angularity between support leg H and lever arm I6 are caused by micrometer screw rotation.

Having thus illustrated and described a preferred embodiment of my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A micro boring and turning device comprising a support provided with a shank receivable in the tool post of alathe 'or other suitable machine tool, a lever pivoted to the support, a tool carried by the lever, an oscillatory nut element 'carried by the lever at a -point remote from its pivot, an opposed oscillatory nut element carried by the support, said nutV elements oscillating around axes parallel with the lever axis, and a micrometer screw having threaded portions provided with threads ofA diierent pitch, each of said threaded portions cooperating with one of said oscillatory nut elements. v

2. A micro boring and turning device comprising a support mountable in the tool post of a lathe or other machine tool, a lever pivoted to support at the end thereof where its legs are joined, a tool carried by one arm of the lever, the other leg of the support and the other arm of the lever being disposed alongside each other, and micrometer mechanism carried by and acting between the last mentioned leg and the last mentioned lever arm to eiect adjustments of the lever with respect to the support.

4. A micro boring and turning device comprising a generally U-shaped support having one leg mountable in the tool post of a lathe or other mal chine tool, a bell crank lever pivoted to the supthe support, a tool carried by the lever, and micrometer mechanism carried by and acting between the support and the lever to effect adjustments of the lever with respect to the support, said micrometer mechanism including a Vduplex screw having threaded -portions provided with threads of diierent pitch, one of said threaded portions having as itscooperating nut element an oscillatory member carried by the support, Aand the other of said threaded portions having as its cooperating nut element an oscillatory memberl carried by the lever, said nut elements oscillating around axes parallel with the lever axis.

3. A micro boring and turning device comprising a generally U-shaped support having one leg mountablein the tool post of a lathe or other machine tool, a bellcrank lever pivoted to the leg of the support and the other arm of the lever being disposed alongside each other, and micrometer mechanism carried by and acting betweenthe last-mentioned leg and the last mentioned lever arm to eiect adjustments of the 1ever with respect to the support, said micrometer mechanism including a screw having threaded portions provided with threads of diierent pitch, one of said threaded portions having as its cooperating nut element an oscillatory member carried by the lever, and the other threaded portion having as its cooperating nut element an oscillatory member carried by the support, said nut elements oscillating around axes parallel with the lever axis.

5. A micro boring and turning device comprising a generally U-shaped support having one leg mountable in the tool post of a lathe or other machine tool, a bell crank lever pivoted to the support at the end thereof where its legs are jomed, a tool carried by one arm of the lever, the other leg of the support and the other arm of the lever being disposed alongside each other with the leg provided with a longitudinal rabbet to accommodate the lever, and micrometer mechanism carried by and acting between the last mentioned leg and the last mentioned arm to eiect adjustments of the lever with respect to the support. 6. lA micro boring and turning device comprising a generally U-shaped support having one leg mountable in the tool post of a lathe or other .suitable machine tool, the legs of the support bemg connected by spaced-apart Webs which constitute lever pivoting ears, a bell crank lever lying between and pin-pivoted to said ears one arm of the lever being shorter than the other, a tool carried by the short arm of the lever the long arm of the lever being disposed alongside that leg of the support which is not mountable in the tool post, extremities of the last mentioned leg and the last mentioned' arm lying closely adjacent to each other, a pair of oscillatory nut elements, each of such nut elements being carried by one of said extremities and oscillating around an axis parallel with the lever axis, and a micrometer screw having4 threaded portions provided with threads of diierent pitch, each of said threaded portions cooperating'with one of said oscillatory nut elements.`

7. A micro boring and turning device comprising a support mountable in the toolY postoffa lathe or other machine tool, a lever pivoted to the support, a tool kcarried by the lever, a pair of oscillatory nut elements, one of said nutv elements being carried by the lever and the other by the support, said nut elements oscillatingv around axes parallel with the lever axis, and a micrometer screw having threaded portions provided with threads of different pitch, each 'of y'said threaded portions cooperating with one of said oscillatory nut elements.

8. A micro boring and turning device compriscrometer mechanism `carried by and acting between the support and the lever to effect adjust-l ments of the lever with respect to the support,A

said micrometer mechanism including a. duplex screw having threaded portions provided with threads of different pitch, one of said threaded portions having a cooperating nut element carried by the support, and the other of said threaded portions having a cooperating nut element carried by the lever, at least one of said nut elements oscillating around an axis parallel with the lever axis.

CHARLES M. KOUBA. 

